Plant extracts as utilized in the present invention are plant juices directly obtained from the fresh plants, juices pressed out of fresh plants both in their original concentration, as well as, in concentrated form, filtered and unfiltered, hydrophilic (aqueous or alcoholic for example ethanol or 1,2-propylene glycol) extracts, as for example, homeopathic prototinctures, fluid extracts, macerates, lipophilic extracts (for example, garlic oil), etheric oils, total extracts or special standardized extracts (for example, having a particular content of flavoneglycocides) etheric oil extracts, individually isolated plant content materials (for example, rutin) synthetic analogs (such as, perfume oils, camphor, thymol, vanillin) and derivatized plant content materials (such as, aglyca).
In the individual cases dry extracts can also be used for example when the dry extract is again dissolved in the appropriate solvent, or decoctions produced therefrom. Furthermore, pulverized drug precursor materials for example, leaves, roots, herbs, etc. may thus be processed.
Plant extracts are natural products which in many cases are sensitive to outside influences such as light, oxidation by atmospheric oxygen, warmth, pH influences in solutions, or microbial attack. It is well known that for many active plant materials the optimal activity can only be obtained from fresh juices obtained from the plant or parts thereof (i.e. echinacea, pressed juice or aloe vera juice). Every procedure for conservation such as drying with heat, chemical conservation, heat treatment for conservation and the like influence the sensitive plant content material with respect to its chemical structure and thus, its activity. In most cases where fresh plant juices are involved, conservation against microbial attack is unavoidable in order to obtain at least a modest shelf life.
Furthermore, it should be realized that the dry content of such fresh plant juices is very small and it is necessary to transport or store large quantities of water.
Oxidation sensitive lipophilic plant extracts such as Vitamin E or garlic oil are exceedingly difficult to store in an unaltered form and must therefore be processed immediately. Etheric oils are very volatile and are difficult to handle in the fluid state. The task of the present invention therefore is to provide preservative free, shelf stable, concentrated, solid or semi-solid forms of plant extracts which can be readily redissolved and whose pharmacological or cosmetic properties, in comparison to the native plant juices remain unchanged.